Abstract: The present invention is a drive system for a boat propeller, with a motor and a reverse gearbox. For forward travel a hydrodynamic coupling is provided and for reverse travel a hydrodynamic reverse converter is provided. The coupling is operated with its maximum filling degree in the upper range of the propeller speed, but in the lower range of propeller speed with a partial filling. Thus, the hydrodynamic coupling is the single hydrodynamic power transfer unit for the entire forward speed range. In order for the boat to be able to be quickly braked down from full speed, the reverse converter is arranged to provide a high torque conversion in the reactive braking range.

Abstract: A hydrodynamic brake has a rotor blade wheel and a stator blade wheel with oblique blades and which together form a toroidal work chamber. A series of quick blades are mounted on the stator blade wheel for controlling the flow of braking fluid between the blade wheels and thereby the degree of braking action. Each of said blades is mounted for rotation around a radial axis and can be swung uniformly by means of a common actuating device. In this basic position, the guide blades are parallel to the stationary blades to provide the maximum flow of braking fluid. In a "zero position" the blades are all in a plane normal to the axis of rotation of the brake, whereby they substantially block the flow of braking fluid within the work chamber. In order to control the braking action, the guide blades may be brought into any desired intermediate position.

Abstract: A hydrodynamic coupling for driving pumps, fans, and the like at variable shaft speeds includes coaxial primary and secondary impellers. The space defined within these impellers contains variable quantities of working fluid for transmitting the shaft torque from one impeller to the other. One of the impellers is equipped with a co-rotating casing, which encloses the other impeller and may serve to force working fluid into the working chamber. The fluid exits from the working chamber through an aperture in the higher-lying impeller and returns to a storage chamber from which a conduit transports it to the casing. A control valve in the conduit permits external flow control.